<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>双飞翼布局</title>
    <!-- <link rel="stylesheet" href="css/index.css"> -->
</head>
<style>
    * {
  margin: 0;
  padding: 0; }

.center {
  width: 100%;
  height: 500px;
  background: plum;
  float: left; }
  .center .content {
    height: 500px;
    padding: 0 300px 0 200px;
    background: yellow; }

.left {
  width: 200px;
  background: orange;
  position: relative;
  float: left;
  height: 500px;
  margin-left: -100%; }

.right {
  float: left;
  width: 300px;
  height: 500px;
  background: pink;
  margin-left: -300px;
  position: relative; }
</style>
<body>
    <!-- 左右两边固定 中间自适应 -->
    <div class="main">
        <div class="center">
            <div class="content">
            有惺惺惜惺惺想寻寻寻寻寻寻寻寻寻寻寻寻寻寻寻寻寻的点点滴滴多多多多多多多多多多多多多多多少时诵诗书所所所所所所所所所所所所所所所所所所的点点滴滴多多多多多多多多多多多多的点点滴滴多多多多多多多多多多多多多多多多多多
            </div>
        </div>
        <div class="left">
            左
        </div>
        <div class="right">
            右
        </div>
    </div>
</body>
</html>